The kinetics of indium/amorphous-selenium multilayer thin film reactions

The reaction kinetics in vapor-deposited indium/amorphous-selenium (a-Se) multilayer thin films were studied using differential scanning calorimetry (DSC), x-ray diffraction (XRD), and transmission electron microscopy (TEM). A number of reactions were observed upon heating with characteristic temperatures which were found to be independent of the multilayer modulation wavelength. The initial interface reaction between In and a-Se is the formation of an In₂Se phase. Kinetic analyses of the In₂Se formation process combined with TEM observations indicated that interface reaction is characterized by the two-dimensional growth of pre-existing In₂Se regions formed during deposition to impingement in the plane of the original In/a-Se interface. The change of the density of In₂Se grains with temperature was analyzed in terms of the derived kinetic parameters, which is consistent with TEM observations and the heat release measurements.